The present invention involves the field of medical devices. More particularly, it involves the field of percussive medical devices used as chiropractic adjustment tools to move bones and relieve muscle spasms and stress.
Percussion is a treatment modality for those who suffer from musculoskeletal pain and myofascial trigger syndrome. It is a non-surgical, non-invasive procedure that may serve as a therapeutic alternative to trigger point and epidural injections or be used when other treatments have failed. Performed on an outpatient basis, percussive treatment carries little or no risk and is relatively comfortable.
As is well-known in the chiropractic art, the spines or other bones of humans sometimes go out of alignment or are otherwise mis-adjusted. This can lead to discomfort and additional physical symptoms. In such cases an adjustment of the spine or other bone to a healthy alignment can have substantial therapeutic effects.
Several attempts have been made to provide hand-held or other small devices to assist in adjusting a patient""s spine or other bone by the use of impacts. However, each of these devices provide limited force, are subject to failure, and have limited application and adjustability.
Needed in the field is a single device permitting both multiple impacts and single impacts. The present invention is directed to this shortcoming in the prior art, specifically to the improvement of the prior art in providing a device that may be used selectively for single impacts or multiple impacts.
The present invention provides a chiropractic adjustment tool or tapper that generally comprises a housing, and a motor or power source to drive an axially reciprocating rod. The reciprocating rod is disposed perpendicularly or near perpendicular to the handle. One end of reciprocating rod extends from the housing and on the extended end is a impact end with a coupler for the mounting of one or more impact heads. The other end of the reciprocating rod has a spring pair assembly to permit the ready adjustment of impact force and axial travel of the reciprocating rod.
A fan may be affixed to the housing and air is used to cool the device components including the motor, switches and circuitry.
The operation of the device is with a solenoid driving the reciprocating rod axially. The reciprocating rod is slideably mounted within the housing, transiting through the solenoid coil. The reciprocating rod is held in place by springs, affixed to the reciprocating rod to limit travel and to return the reciprocating rod to the neutral position between impacts. On activation, the reciprocating rod is accelerated axially by the solenoid. Mounted on the extended end of the reciprocating rod is one of a number of impact heads. An impact head is used to impact the patient""s body. When the solenoid is reactivated, the reciprocating rod is again accelerated toward the patient""s body. A typical rate of impact is twelve impacts per second. Both the speed and the force of impact are adjustable to provide optimal therapeutic effects. In a preferred embodiment, the travel and force of impact of the reciprocating rod is adjusted by adjusting the compression of the spring pair.
Though the device may be used in a manner that provides continuous pressure punctuated by impacts, the assembly also permits an impact head to provide instantaneous force without durational pressure. This is accomplished through the use of an accelerated reciprocating rod that is permitted to bounce or recoil off of the patient, providing impact force without pressure of any duration. This is advantageous as durational pressure is painful and increases bruising.
As it is desirable to be able to selectively convert the provided device from a multiple impact device to a single impact device, the specific improvement of this invention is related to this selection means. In a standard reciprocating device, circuitry provides for the device to cycle and for the impact head to rapidly reciprocate. A skilled user may be able to quickly activate and deactivate the device and allow a single impact, however when rapidly reciprocating at twelve cycles per second, this becomes difficult.
Provided is a means to deactivate the device after a single impact. Mechanical stops or locks, photoelectric or electromechanical switches triggered by activation may be used but have an unacceptable failure rate due partly to the percussive nature of the device.
Other methods of controlling the number of impacts may be accomplished through the use of complex logic circuits. However such systems become increasingly expensive due to synchronization and other problems. The very nature of the device in use involves percussive therapy. Complex logic circuits able to withstand the percussive nature of the device tend to increase component costs and failure rates.
To overcome this problem, disclosed is a of method and embodiment of selectively limiting this device to a single stroke through the use of a solid state Hall effect switch.
The Hall effect switch is comprised of a Hall effect sensor, such as those produced by Allegro Microsystems, Inc., part no. A3187LU, placed proximate the south pole of the solenoid. Other placements are available including placing a Hall effect sensor proximate the lead wire used to power the solenoid. The Hall effect sensor is integrated with the balance of the circuitry of the device. When the solenoid of the impact device is charged, a magnetic field is created and sensed by the Hall effect sensor. The Hall effect sensor then produces a current transmitted to the controlling circuitry which deactivates the Solenoid, limiting the function of the device to a single impact.
The conversion of the invention from a single impact device to a multiple impact device may be easily accomplished through the deactivation or bypassing of the Hall effect sensor.